U499016求时间优化方案

#include<bits/stdc++.h>
#include<cmath>
using namespace std;

int main () {
    int p[100001][4],n;
    double k;
    cin>>n>>k;
    int ans=0;
    for(int i=0;i<=n;i++){
        for(int j=0;j<=n-i;j++){
            //cout<<i<<" "<<j<<endl;
            for(int m=ceil(n*1.0/(n-i-j+1));m<=i+j;m++){
                if(round(i*900000.0/n+j*585000.0/n+m*100000.0/n)==k){
                    p[ans][0]=i;
                    p[ans][1]=j;
                    p[ans][2]=n-i-j;
                    p[ans][3]=m;
                    ans++;
                }
            }
        }
    }
    if(ans==0){
        cout<<"No solution!";
    }else{
        cout<<ans<<endl;
        for(int i=0;i<ans;i++){
            cout<<p[i][0]<<" "<<p[i][1]<<" "<<p[i][2]<<" "<<p[i][3]<<endl;
        }
    }
    return 0;
}

题目U499016，求优化方法

感谢各位大佬